The Type-62 was the smaller version of the Type-59. I am in process of doing a review of the Trumpeter kit.
For the NVA question, as of right now, there is no consensus on if there were only Type-59, only T-54, or a mix. Since there is no OOB ready Type-59, take a leap and build a T-54 as one.
I'm inclined to agree with the above, but I WOULD like to find out which tanks the NVA used during the Vietnam War.
Just a comment- Some years ago, I converted a TAMIYA T-55 into a T-54 by using the SP DESIGNS T-54 Conversion. I'm not sure (not being a dyed-in-the-wool Russo-Soviet fan) if the SP DESIGNS Conversion is 100% "spot-on". Maybe someone can set me straight? Comments, anyone?